Abstract: In this paper, a set of experimental data has been used to assess the influence of abrasive water jet (AWJ) process parameters in cutting 6063-T6 aluminum alloy. The process variables considered here include nozzle diameter, jet traverse rate, jet pressure and abrasive flow rate. The effects of these input parameters are studied on depth of cut (h); one of most important characteristics of AWJ. The Taguchi method and regression modeling are used in order to establish the relationships between input and output parameters. The adequacy of the model is evaluated using analysis of variance (ANOVA) technique. In the next stage, the proposed model is embedded into a Simulated Annealing (SA) algorithm to optimize the AWJ process parameters. The objective is to determine a suitable set of process parameters that can produce a desired depth of cut, considering the ranges of the process parameters. Computational results prove the effectiveness of the proposed model and optimization procedure.
Abstract: Wheat has a bimodal starch granule population and the dependency of the rate of enzymatic hydrolysis on particle size has been investigated. Ungelatinised wheaten starch granules were separated into two populations by sedimentation and decantation. Particle size was analysed by laser diffraction and morphological characteristics were viewed using SEM. The sedimentation technique though lengthy, gave satisfactory separation of the granules. Samples (10μm and original) were digested with a-amylase using a dialysis model. Granules of 10μm (p10μm. Moreover, the digestion rate was dependent on particle size whereby smaller granules produced higher rate of release. The methodology and results reported here can be used as a basis for further evaluations designed to delay the release of glucose during the digestion of native starches.
Abstract: Energy consumption is a very important topic these
days especially regarding air conditioning in residential buildings,
since this takes the biggest amount of energy in buildings total
consumption, residential buildings constitute the biggest percentage
of energy consumption in Bahrain.
This research reflects on the effects of shading percentage in
different solar orientations on the energy consumption inside
residential buildings (domestic dwellings).
The research as found that, there are different effects of shading in
changing building orientation:
• 0.69% for the shading percentage 25% when the building is
oriented to the north (0º);
• 18.59% for 75% of shading in north-west orientation
(325º);
• The best effect for shading is in north-west orientation
(315º);
• The less effect for shading was in case of the building
orientation is the north (0º).
Abstract: This paper studied the synthesis of monoacylglycerol (monolaurin) by glycerolysis of coconut oil and crude glycerol, catalyzed by Carica papaya lipase. Coconut oil obtained from cold pressed extraction method and crude glycerol obtained from the biodiesel plant in Department of Chemistry, Uttaradit Rajabhat University, Thailand which used oils were used as raw materials for biodiesel production through transesterification process catalyzed by sodium hydroxide. The influences of the following variables were studied: (i) type of organic solvent, (ii) molar ratio of substrate, (iii) reaction temperature, (iv) reaction time, (v) lipase dosage, and (vi) initial water activity of enzyme. High yields in monoacylglycerol (58.35%) were obtained with molar ratio of glycerol to oil at 8:1 in ethanol, temperature was controlled at 45oC for 36 hours, the amount of enzyme used was 20 wt% of oil and initial water activity of enzyme at 0.53.
Abstract: Formulation of biological profile is one of the modern roles of forensic anthropologist. The present study was conducted to estimate height using foot and shoeprint length of Malaysian population. The present work can be very useful information in the process of identification of individual in forensic cases based on shoeprint evidence. It can help to narrow down suspects and ease the police investigation. Besides, stature is important parameters in determining the partial identify of unidentified and mutilated bodies. Thus, this study can help the problem encountered in cases of mass disaster, massacre, explosions and assault cases. This is because it is very hard to identify parts of bodies in these cases where people are dismembered and become unrecognizable. Samples in this research were collected from 200 Malaysian adults (100 males and 100 females) with age ranging from 20 to 45 years old. In this research, shoeprint length were measured based on the print of the shoes made from the flat shoes. Other information like gender, foot length and height of subject were also recorded. The data was analyzed using IBM® SPSS Statistics 19 software. Results indicated that, foot length has a strong correlation with stature than shoeprint length for both sides of the feet. However, in the unknown, where the gender was undetermined have shown a better correlation in foot length and shoeprint length parameter compared to males and females analyzed separately. In addition, prediction equations are developed to estimate the stature using linear regression analysis of foot length and shoeprint length. However, foot lengths give better prediction than shoeprint length.
Abstract: Aircraft propulsion systems often use Y-shaped
subsonic diffusing ducts as twin air-intakes to supply the ambient air
into the engine compressor for thrust generation. Due to space
constraint, the diffusers need to be curved, which causes severe flow
non-uniformity at the engine face. The present study attempt to
control flow in a mild-curved Y-duct diffuser using trapezoidalshaped
vortex generators (VG) attached on either both the sidewalls
or top and bottom walls of the diffuser at the inflexion plane. A
commercial computational fluid dynamics (CFD) code is modified
and is used to simulate the effects of SVG in flow of a Y-duct
diffuser. A few experiments are conducted for CFD code validation,
while the rest are done computationally. The best combination of Yduct
diffuser is found with VG-2 arranged in co-rotating sequence
and attached to both the sidewalls, which ensures highest static
pressure recovery, lowest total pressure loss, minimum flow
distortion and less flow separation in Y-duct diffuser. The decrease in
VG height while attached to top and bottom walls further improves
axial flow uniformity at the diffuser outlet by a great margin as
compared to the bare duct.
Abstract: Numerical design optimization is a powerful tool that
can be used by engineers during any stage of the design process.
There are many different applications for structural optimization. A
specific application that will be discussed in the following paper is
experimental data matching. Data obtained through tests on a physical
structure will be matched with data from a numerical model of that
same structure. The data of interest will be the dynamic characteristics
of an antenna structure focusing on the mode shapes and modal
frequencies. The structure used was a scaled and simplified model of
the Karoo Array Telescope-7 (KAT-7) antenna structure.
This kind of data matching is a complex and difficult task. This
paper discusses how optimization can assist an engineer during the
process of correlating a finite element model with vibration test data.
Abstract: The paper investigates the relationship between the foreign direct investment (FDI) and the corporate governance or transparency by investigating the country-level FDI flows, FDI inward performance, corporate governance and transparency variables. From the regression analysis with Newey-West estimator of 28 country panel data from 1990- 2002, we find strong positive relationships between corporate governance or transparency level of hosting countries and FDI inward performance within hosting countries. A strong positive relationship is found between anti-director rights level or number of analysts of hosting countries and FDI inward performance within hosting countries. Also, we find a positive relationship between the number of analysts of hosting countries and FDI inflows. The empirical results are consistent with stock market liberalizations and corporate governance explanations of reasons for FDI.
Abstract: Dichotomization of the outcome by a single cut-off point is an important part of various medical studies. Usually the relationship between the resulted dichotomized dependent variable and explanatory variables is analyzed with linear regression, probit regression or logistic regression. However, in many real-life situations, a certain cut-off point dividing the outcome into two groups is unknown and can be specified only approximately, i.e. surrounded by some (small) uncertainty. It means that in order to have any practical meaning the regression model must be robust to this uncertainty. In this paper, we show that neither the beta in the linear regression model, nor its significance level is robust to the small variations in the dichotomization cut-off point. As an alternative robust approach to the problem of uncertain medical categories, we propose to use the linear regression model with the fuzzy membership function as a dependent variable. This fuzzy membership function denotes to what degree the value of the underlying (continuous) outcome falls below or above the dichotomization cut-off point. In the paper, we demonstrate that the linear regression model of the fuzzy dependent variable can be insensitive against the uncertainty in the cut-off point location. In the paper we present the modeling results from the real study of low hemoglobin levels in infants. We systematically test the robustness of the binomial regression model and the linear regression model with the fuzzy dependent variable by changing the boundary for the category Anemia and show that the behavior of the latter model persists over a quite wide interval.
Abstract: The purpose of this study is to determine in what
ways elementary education prospective teachers are being informed
about innovations and to explain the role of social influence in the
usage process of a technological innovation in terms of genders. The
study group consisted of 300 prospective teachers, including 234
females and 66 males. Data have been collected by a questionnaire
developed by the researchers. The result of the study showed that,
while prospective teachers are being informed about innovations
most frequently by mass media, they rarely seek to take expert
advice. In addition, analysis of results showed that the social
influence on females were significantly higher than males in usage
process of a technological innovation.
Abstract: The measurements of 226Ra, 232Th and 40K using
gamma spectrometry and radon concentration and exhalation rates
measurements using solid state nuclear track (LR-115, Type-II
plastic) detectors are used to asses a first order exposure risk for the
persons residing in Fatehbad and Hissar districts of Western Haryana,
India. The concentration of Radium, Thorium and Potassium in the
soil samples varies from 13.37 Bq m-3 to 24.67 Bq m-3, 34.67 Bq m-3
to 67.34 Bq m-3 and 298.78 Bq m-3 to 405.67 Bq m-3 respectively
with average values of 18.78, 47.35 and 361.57 Bq m-3 respectively.
The radium equivalent activity (Raeq) calculated for the same soil
samples varies from 92.72 Bq m-3 to 140.6 Bq m-3 with an average
value of 111.80 Bq m-3. The values of absorbed dose and annual
effective dose (indoors and outdoors) are found to vary from 44.18
nGy h-1 to 65.23 nGy h-1, 0.22 mSv y-1 to 0.32 mSv y-1 and 0.05 mSv
y-1 to 0.08 mSv y-1 respectively. The radon concentration and
exhalation rates have also been reported. The radium equivalent
activities in all the soil samples were found to be lower than the limit
(370 Bq kg-1) set in the Organization for Economic Cooperation and
Development (OECD) report and the value of Hex in all the samples
is less than unity.
Abstract: A stack with a small critical temperature gradient is
desirable for a standing wave thermoacoustic engine to obtain a low
onset temperature difference (the minimum temperature difference to
start engine-s self-oscillation). The viscous and heat relaxation loss in
the stack determines the critical temperature gradient. In this work, a
dimensionless critical temperature gradient factor is obtained based
on the linear thermoacoustic theory. It is indicated that the
impedance determines the proportion between the viscous loss, heat
relaxation losses and the power production from the heat energy. It
reveals the effects of the channel dimensions, geometrical
configuration and the local acoustic impedance on the critical
temperature gradient in stacks. The numerical analysis shows that
there exists a possible optimum combination of these parameters
which leads to the lowest critical temperature gradient. Furthermore,
several different geometries have been tested and compared
numerically.
Abstract: The aim of the article is to describe modern
contemporary systems of employees' remuneration used in
organizations, to give a general overview of these questions based on
the questionnaire survey made by the authors, as well as to assess
possible effects of economic crisis in this area. It is necessary to be
aware of the fact that firm's success in the contemporary business
environment depends not only on the technical equipment, financial
resources, availability of raw materials and information and effective
management, but one of the crucial factors of firm's success is its
human potential. The article emphasizes that the well working
remuneration system has a very important position in the
organization in the broadest sense. The paper also aims to the current
situation in the area of employees' remuneration in one of Czech
Republic regions, in the Moravian-Silesian Region.
Abstract: Normally business changes are made in order to
change a level of activity in some way, whether it is sales, cash flow,
productivity, or product portfolio. When attempts are made to make
such changes, too often the business reverts to the old levels of
activity as soon as management attention is diverted. Risk
management is a field of growing interest to project managers as well
as in general business and organizational management. There are
several approaches used to manage risk in projects and this paper is a
brief outline of some that you might encounter, with an indication of
their strengths and weaknesses.
Abstract: In this paper, we investigate the problem of the existence, uniqueness and global asymptotic stability of the equilibrium point for a class of neural networks, the neutral system has mixed time delays and parameter uncertainties. Under the assumption that the activation functions are globally Lipschitz continuous, we drive a new criterion for the robust stability of a class of neural networks with time delays by utilizing the Lyapunov stability theorems and the Homomorphic mapping theorem. Numerical examples are given to illustrate the effectiveness and the advantage of the proposed main results.
Abstract: This study is a descriptive-normative research. It
attempted to investigate the restaurants’ firm performance in terms of
the customers and restaurant personnel’s degree of satisfaction. A
total of 12 restaurants in Bangkok, Thailand that offer Thai cuisine
were included in this study. It involved 24 stockholders/managers,
120 subordinates and 360 customers. General Managers and
restaurants’ stockholders, 10 staffs, and 30 costumers for each
restaurant were chosen for random sampling. This study found that
respondents are slightly satisfied with their work environment but are
generally satisfied with the accessibility to transportation, to malls,
convenience, safety, recreation, noise-free, and attraction; customers
find the Quality of Food in most Thai Cuisines like services, prices of
food, sales promotion, and capital and length of service satisfactory.
Therefore, both stockholder-related and personnel-related factors
which are influenced by restaurant, personnel, and customer-related
factors are partially accepted whereas; customer-related factors which
are influenced by restaurant, personnel and customer-related factors
are rejected.
Abstract: At a time of growing market turbulence and a strong
shifts towards increasingly complex risk models and more stringent audit requirements, it is more critical than ever to maintain the highest quality of financial and credit information. IFC implemented
an approach that helps increase data integrity and quality significantly. This approach is called “Screening". Screening is based on linking information from different sources to identify potential
inconsistencies in key financial and credit data. That, in turn, can help
to ease the trials of portfolio supervision, and improve overall company global reporting and assessment systems. IFC experience
showed that when used regularly, Screening led to improved information.
Abstract: The research is to minimize environmental damage
pertinent to maritime activities about the operation of lighter boat
anchorage and its tugboat. The guidance on upgrading current
harbor service and infrastructure has been provided to Kho Sichang
Municpality. This will involve a study of the maritime logistics of
the water area under jurisdiction of the Sichang island Municipality
and possible recommendations may involve charging taxes,
regulations and fees. With implementing these recommendations will
help in protection of the marine environment and in increasing
operator functionality. Additionally, our recommendation is to
generate a consistent revenue stream to the municipality. The action
items contained in this research are feasible and effective, the success
of these initiatives are heavily dependent upon successful promotion
and enforcement. Promoting new rules and regulations effectively
and peacefully can be done through theories and techniques used in
the psychology of persuasion. In order to assure compliance with the
regulations, the municipality must maintain stringent patrols and
fines for violators. In order to become success, the Municipality
must preserve a consistent, transparent and significant enforcement
system. Considering potential opportunities outside of the current
state of the municipality, the authors recommend that Koh Sichang be
given additional jurisdiction to capture value from the master vessels,
as well as to confront the more significant environmental challenges
these vessels pose. Finally, the authors recommend that the Port of
Koh Sichang Island obtain a free port status in order to increase
economic viability and overall sustainability.
Abstract: The present paper is an experimental investigation of
roughness effects on nucleate pool boiling of refrigerant R113 on
horizontal circular copper surfaces. The copper samples were treated
by different sand paper grit sizes to achieve different surface
roughness. The average surface roughness of the four samples was
0.901, 0.735, 0.65, and 0.09, respectively. The experiments were
performed in the heat flux range of 8 to 200kW/m2. The heat transfer
coefficient was calculated by measuring wall superheat of the
samples and the input heat flux. The results show significant
improvement of heat transfer coefficient as the surface roughness is
increased. It is found that the heat transfer coefficient of the sample
with Ra=0.901 is 3.4, 10.5, and 38.5% higher in comparison with
surfaces with Ra of 0.735, 0.65, and 0.09 at heat flux of 170 kW/m2.
Moreover, the results are compared with literature data and the well
known Cooper correlation.
Abstract: In this study, a double-sided linear switched reluctance
motor (LSRM) drive was investigated as an alternative actuator for
vertical linear transportation applications such as a linear elevator
door, hospital and subway doors which move linearly and where
accurate position control and rapid response is requested. A prototype
sliding elevator door that is focused on a home elevator with LSRMs
is designed. The motor has 6/4 poles, 3 phases, 8A, 24V, 250 W and
250 N pull forces. Air gap between rotor and translator poles of the
designed motor and phase coil-s ideal inductance profile are obtained
in compliance with the geometric dimensions. Operation and
switching sections as motor and generator has been determined from
the inductance profile.